Does the Combination of Finnish Sauna Bathing and Other Lifestyle Factors Confer Additional Health Benefits? A Review of the Evidence.

Sauna bathing, a tradition deeply rooted in the Finnish culture, has been used for thousands of years for leisure, relaxation, and wellness. Sauna bathing is linked with substantial health benefits beyond its use for leisure and relaxation. Several observational and interventional studies suggest that regular or frequent sauna bathing reduces the incidence of vascular and nonvascular diseases, such as hypertension, cardiovascular disease, dementia, and respiratory conditions; may improve the severity of conditions such as musculoskeletal disorders, COVID-19, headache, and influenza; and increases the life span. The beneficial effects of sauna bathing on adverse outcomes have been linked to its blood pressure-reducing, anti-inflammatory, antioxidant, cytoprotective, and stress-reducing properties and its synergistic effect on neuroendocrine, circulatory, cardiovascular, and immune function. Evidence suggests that frequent sauna bathing is an emerging protective risk factor that may augment the beneficial effects of other protective risk or lifestyle factors, such as physical activity and cardiorespiratory fitness, or attenuate or offset the adverse effects of other risk factors, such as high blood pressure, systemic inflammation, and low socioeconomic status. This review summarizes the available epidemiologic and interventional evidence linking the combined effects of Finnish sauna bathing and other risk factors on vascular outcomes including cardiovascular disease and intermediate cardiovascular phenotypes, nonvascular outcomes, and mortality. We also discuss the mechanistic pathways underlying the joint contributions of Finnish sauna bathing and other risk factors on health outcomes, the public health and clinical implications of the findings, gaps in the existing evidence base, and future directions.

Associations of resting and peak fat oxidation with sex hormone profile and blood glucose control in middle-aged women.

BACKGROUND AND AIMS: Menopause may reduce fat oxidation. We investigated whether sex hormone profile explains resting fat oxidation (RFO) or peak fat oxidation (PFO) during incremental cycling in middle-aged women. Secondarily, we studied associations of RFO and PFO with glucose regulation. METHOD AND RESULTS: We measured RFO and PFO of 42 women (age 52-58 years) with indirect calorimetry. Seven participants were pre- or perimenopausal, 26 were postmenopausal, and nine were postmenopausal hormone therapy users. Serum estradiol (E2), follicle-stimulating hormone, progesterone, and testosterone levels were quantified with immunoassays. Insulin sensitivity (Matsuda index) and glucose tolerance (area under the curve) were determined by glucose tolerance testing. Body composition was assessed with dual-energy X-ray absorptiometry; physical activity with self-report and accelerometry; and diet, with food diaries. Menopausal status or sex hormone levels were not associated with the fat oxidation outcomes. RFO determinants were fat mass (ß = 0.44, P = 0.006) and preceding energy intake (ß = -0.40, P = 0.019). Cardiorespiratory fitness (ß = 0.59, P = 0.002), lean mass (ß = 0.49, P = 0.002) and physical activity (self-reported ß = 0.37, P = 0.020; accelerometer-measured ß = 0.35, P = 0.024) explained PFO. RFO and PFO were not related to insulin sensitivity. Higher RFO was associated with poorer glucose tolerance (ß = 0.52, P = 0.002). CONCLUSION: Among studied middle-aged women, sex hormone profile did not explain RFO or PFO, and higher fat oxidation capacity did not indicate better glucose control.

Attenuated Risk of Pneumonia Due to Inflammation by Frequent Sauna Baths: A PROSPECTIVE COHORT STUDY.

PURPOSE: Inflammatory pathways are involved in the pathogenesis of pneumonia. Frequent sauna sessions may reduce the risk of respiratory tract infections including pneumonia independent of inflammation. We aimed to evaluate the independent and joint associations of high-sensitivity C-reactive protein (hsCRP) and frequency of sauna bathing (FSB) with risk of pneumonia in a prospective cohort study. METHODS: Serum hsCRP as an inflammatory marker was measured using an immunometric assay and FSB was assessed by self-reported sauna bathing habits at baseline in 2264 men aged 42-61 yr. Serum hsCRP was categorized as normal and high (≤3 and >3 mg/L, respectively) and FSB as low and high (defined as ≤1 and 2-7 sessions/wk, respectively). Multivariable-adjusted HRs (CIs) were calculated for incident pneumonia. RESULTS: A total of 528 cases of pneumonia occurred during a median follow-up of 26.6 yr. Comparing high versus normal hsCRP, the multivariable-adjusted risk for pneumonia was HR = 1.30 (95% CI, 1.04-1.62). The corresponding risk was HR = 0.79 (95% CI, 0.66-0.95) comparing high versus low FSB. Compared with men with normal hsCRP and low FSB, high hsCRP and low FSB was associated with an increased risk of pneumonia in multivariable analysis (HR = 1.67: 95% CI, 1.21-2.29), with no evidence of an association for high hsCRP and high FSB and pneumonia (HR = 0.94: 95% CI, 0.69-1.29). CONCLUSIONS: In a general middle-aged to older male Caucasian population, frequent sauna baths attenuated the increased risk of pneumonia due to inflammation.

Delphi consensus recommendations on how to provide cardiovascular rehabilitation in the COVID-19 era.

This Delphi consensus by 28 experts from the European Association of Preventive Cardiology (EAPC) provides initial recommendations on how cardiovascular rehabilitation (CR) facilities should modulate their activities in view of the ongoing coronavirus disease 2019 (COVID-19) pandemic. A total number of 150 statements were selected and graded by Likert scale [from -5 (strongly disagree) to +5 (strongly agree)], starting from six open-ended questions on (i) referral criteria, (ii) optimal timing and setting, (iii) core components, (iv) structure-based metrics, (v) process-based metrics, and (vi) quality indicators. Consensus was reached on 58 (39%) statements, 48 'for' and 10 'against' respectively, mainly in the field of referral, core components, and structure of CR activities, in a comprehensive way suitable for managing cardiac COVID-19 patients. Panelists oriented consensus towards maintaining usual activities on traditional patient groups referred to CR, without significant downgrading of intervention in case of COVID-19 as a comorbidity. Moreover, it has been suggested to consider COVID-19 patients as a referral group to CR per se when the viral disease is complicated by acute cardiovascular (CV) events; in these patients, the potential development of COVID-related CV sequelae, as well as of pulmonary arterial hypertension, needs to be focused. This framework might be used to orient organization and operational of CR programmes during the COVID-19 crisis.

Cardiorespiratory Fitness, Inflammation, and the Incident Risk of Pneumonia.

INTRODUCTION: Both inflammation and cardiorespiratory fitness (CRF) are associated with the risk of respiratory infections. To clarify the hypothesis that CRF attenuates the incident risk of pneumonia due to inflammation, we conducted a prospective study examining the independent and joint associations of inflammation and CRF on the risk of pneumonia in a population sample of 2041 middle-aged men. METHODS: Cardiorespiratory fitness was directly measured as peak oxygen uptake (V˙o2peak) during progressive exercise testing to volitional fatigue, and categorized into tertiles. Inflammation was defined by high-sensitivity C-reactive protein (hsCRP). Pneumonia cases were identified by internal medicine physicians using the International Classification of Diseases codes in clinical practice. RESULTS: During a median follow-up of 27 yr, 432 pneumonia cases were recorded. High hsCRP and CRF were associated with a higher risk (HR = 1.38; 95% CI, 1.02-1.88) and a lower risk of pneumonia (HR = 0.55; CI, 0.39-0.76) after adjusting for potential confounders, respectively. Compared with normal hsCRP-Fit, moderate to high hsCRP-Unfit had an increased risk of pneumonia (HR = 1.63; CI, 1.21-2.20), but moderate to high hsCRP-Fit was not associated with an increased risk of pneumonia (HR = 1.25; CI, 0.93-1.68). CONCLUSIONS: High CRF attenuates the increased risk of pneumonia due to inflammation. These findings have potential implications for the prevention of respiratory infection characterized by systemic inflammation, such as coronavirus disease-2019 (COVID-19).

High fitness levels, frequent sauna bathing and risk of pneumonia in a cohort study: Are there potential implications for COVID-19?

BACKGROUND: There is an ongoing debate on a potential protective role of habitual physical activity and passive heat therapy on the risk of COVID-19, a respiratory infectious disease that can manifest as severe pneumonia. To explore these putative roles, we evaluated the independent and joint associations of cardiorespiratory fitness (CRF) and frequency of sauna bathing (FSB) with pneumonia risk in a prospective cohort study of 2275 men aged 42-61 years at recruitment. MATERIAL AND METHODS: Objectively measured CRF and self-reported sauna bathing habits were assessed at baseline. CRF was categorized as low and high (median cut-offs) and FSB as low and high (defined as ≤1 and 2-7 sessions/wk, respectively). Multivariable-adjusted hazard ratios (HRs) with confidence intervals (CIs) were calculated for incident pneumonia. RESULTS: During a median follow-up of 26.6 years, 529 cases of pneumonia occurred. Comparing high vs low CRF, the multivariable-adjusted HR (95% CIs) for pneumonia was 0.75 (0.61-0.91). Comparing high vs low FSB, the corresponding HR was 0.81 (0.68-0.97). Compared to men with low CRF & low FSB, the multivariable-adjusted HRs of pneumonia for the following groups: high CRF & low FSB; low CRF & high FSB; and high CRF & high FSB were 0.88 (0.65-1.20), 0.89 (0.71-1.13), and 0.62 (0.48-0.80) respectively. CONCLUSIONS: In a general male Caucasian population, a combination of high fitness levels and frequent sauna baths is associated with a substantially lowered future pneumonia risk compared with each modality alone. The implications of these findings in altering COVID-19 disease or its severity deserve study.

Sauna bathing frequency in Finland and the impact of COVID-19.

OBJECTIVES: Recent research has revealed multiple potential health benefits of frequent sauna bathing. Finland is a country with extraordinary sauna culture and bathing opportunities. However, coronavirus disease 2019 (COVID-19) pandemic introduced regulations and unprecedented closures to shared sauna facilities. In this study we aimed to examine the previously unknown baseline bathing frequency and its possible change during the epidemic. DESIGN: We investigated several aspects of sauna bathing with self-reports: the frequency, its possible changes, reasons for change, and beliefs about its health effects among a representative sample of thousand Finns aged 18-75 years. This online survey was administered in May 2020. RESULTS: Before the pandemic, 59 % of our respondents had enjoyed sauna at least once a week. Since the pandemic began, up to 23 % had reduced or stopped their bathing. This was often due to restricted sauna access. However, 11 % of respondents bathed more frequently and attributed this change to seeking relaxation and passing time. These findings demonstrate a surprising flexibility in this health-promoting national pastime. Men were more active bathers than women overall and women under 35 enjoy sauna more seldom than older women. Only 7.9 % of all respondents bathed at least four times a week, exceeding a suggested threshold for maximum health benefits. CONCLUSIONS: Finnish people are active sauna bathers. The COVID-19 pandemic demonstrated that the frequency of bathing is dependent on good access to sauna facilities. This flexibility and wide access could be exploited to improve public health in the long term if more frequent bathing became a standard.

Amiodarone in the COVID-19 Era: Treatment for Symptomatic Patients Only, or Drug to Prevent Infection?

Amiodarone, one of the most widely prescribed antiarrhythmic drugs to treat both ventricular and supraventricular arrhythmias, has been identified as a candidate drug for use against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We present the rationale of using amiodarone in the COVID-19 scenario, as well as whether or not amiodarone administration represents a potential strategy to prevent SARS-CoV-2 infection, rather than simply used to treat patients already symptomatic and/or with severe coronavirus disease 2019 (COVID-19), based on current evidence.

Renal complications in COVID-19: a systematic review and meta-analysis.

PURPOSE: Emerging data suggest that coronavirus disease 2019 (COVID-19) has extrapulmonary manifestations but its renal manifestations are not clearly defined. We aimed to evaluate renal complications of COVID-19 and their incidence using a systematic meta-analysis. DESIGN: Observational studies reporting renal complications in COVID-19 patients were sought from MEDLINE, Embase and the Cochrane Library from 2019 to June 2020. The nine-star Newcastle-Ottawa Scale was used to evaluate methodological quality. Incidence with 95% confidence intervals (CIs) were pooled using random-effects models. RESULTS: We included 22 observational cohort studies comprising of 17,391 COVID-19 patients. Quality scores of studies ranged from 4 to 6. The pooled prevalence of pre-existing chronic kidney disease (CKD) and end-stage kidney disease was 5.2% (2.8-8.1) and 2.3% (1.8-2.8), respectively. The pooled incidence over follow-up of 2-28 days was 12.5% (10.1-15.0) for electrolyte disturbance (e.g. hyperkalaemia), 11.0% (7.4-15.1) for acute kidney injury (AKI) and 6.8% (1.0-17.0) for renal replacement therapy (RRT). In subgroup analyses, there was a higher incidence of AKI in US populations and groups with higher prevalence of pre-existing CKD. CONCLUSIONS: Frequent renal complications reported among hospitalized COVID-19 patients are electrolyte disturbance, AKI and RRT. Aggressive monitoring and management of these renal complications may help in the prediction of favourable outcomes. Systematic review registration: PROSPERO 2020: CRD42020186873 KEY MESSAGES COVID-19 affects multiple organs apart from the respiratory system; however, its renal manifestations are not clearly defined. In this systematic meta-analysis of 22 observational cohort studies, the prevalence of pre-existing chronic kidney disease (CKD) in COVID-19 patients was 5.2%. The most frequent renal complication was electrolyte disturbance (particularly hyperkalaemia) with an incidence of 12.5% followed by acute kidney injury (AKI) with an incidence of 11.0%; US populations and groups with higher prevalence of CKD had higher incidence of AKI.